1. Technical Field
The disclosure relates in general to a method and a system of service channels in a vehicular environment, and more particularly to a method and a system for switching service channels in a vehicular environment.
2. Description of the Related Art
Due to the maturity in the technology of wireless communication, navigation, and on-board electronics, many countries are dedicated to the research and development in the vehicular communication technology with an attempt to creating new industries. Considering the high mobility and instantaneity of the vehicles as well the characteristics of a wireless network itself, it is acknowledged that there are significant differences between the demands for communications in vehicular environment and commonly used wireless communication technologies such as 3.5G and Wi-Fi. Thus, the IEEE Standard Association develops a set of protocols for on-board communication, such as IEEE 1609 for wireless access in vehicular environment (WAVE), which includes a protocol group for processing respective layers of the network OSI model and performing communication with the accompany of the IEEE 802.11p physical layer.
In the bottom layer of IEEE 1609 protocol, the channels are divided into a control channel and several service channels. The control channel is for transmitting emergency information and used as a channel via which a service provider sends a broadcast packet to inform the users within the coverage of communication about the information of the services provided by the service provider and the service channels belonging to the service provider. The service channels are for transmitting various services. Due to the restrictions on the communication hardware as stipulated in the protocol, the service provider end should employ at least two antennas: one for the control channel and the other for the service channel. When the user end uses a single antenna, only one channel can be monitored at a time. Thus, the protocol provides the user with a mode in which the control channel and the service channel are being switched alternately with an equal ratio in time. In addition, the protocol has been updated to introduce a functionality of extending the time limit of the service channel, wherein the user end pre-determines an extension interval. However, the restrictions on the communication hardware remain unchanged, and the flexibility and the channel utilization rate are still insufficient for both the service provider end and the user end.